ARulesXL is an excellent tool for implementing audit applications, as required, for example, by Sarbanes Oxley.
An audit application is composed of financial form templates and associated audit rules. Company data is mapped into the templates, the audit rules are applied and the analysis is output.
Because the rules are declarative, they are easy to write, easy to read and easy to verify as correct.
The following screen shots show a simple example using basic balance sheets and income statements for two successive periods.
The green cells are intended to contain values from actual company financial statements. The rules are on a separate worksheet described later.
The light blue cells contain the output analysis. In this case the balance statement for the current period is incorrect, as is the capital for that report.
The output is just a simple description in the example. Full text reports could be generated instead, or the cells of the financial templates could be flagged with Excel comments.
As can be seen in the function window, the output is generated by an RQuery() call to the rule engine, asking for the value of the fact Problems.
The rules are entered in an ARulesXL rule set.
The first four lines, starting with RArray: are function calls that read the financial templates into the rule engine.
The different types of problem are represented as elements in an array of problems, where the index into the array is a small description of the problem itself. Each rule states the conditions under which that problem applies.
The last rule makes a list of all of the problems that apply.
The rules can be as complex as desired, and can refer to other rules for analyzing complex relationships between different areas of the financial statements.
The rule sets can be modularized, so there are different rule sets performing different parts of the audit.